Sign post



FIG. 1 is a front perspective view of a sign post, the broken lines forming no part of the claimed design;

FIG. 2 is a front view of the sign post of FIG. 1;

FIG. 3 is a rear view of the sign post of FIG. 1;

FIG. 4 is a view from a first side of the sign post of FIG. 1;

FIG. 5 is a view from a second side of the sign post of FIG. 1;

FIG. 6 is top view of the sign post of FIG. 1; and,

FIG. 7 is a bottom of the sign post of FIG. 1. 

The ornamental design for a sign post, as shown and described. 